Stochastic model of the still water bending moment of oil tankers

2009 ◽  
pp. 483-494 ◽  
Author(s):  
E Rizzuto ◽  
L Garrè
Keyword(s):  
Stochastic Model ◽  
Bending Moment ◽  
Oil Tankers

The Effect of Sloshing in Tanks on Motions and Hull Girder Responses of Damaged Vessels

2011 ◽  
Author(s):  
Huirong Jia ◽  
Torgeir Moan
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Bending Moment ◽  
Roll Motion ◽  
Multimodal Approach ◽  
Rectangular Shape ◽  
Hull Girder ◽  
Structural Reliability Analysis ◽  
Oil Tankers

The structural reliability analysis of damaged vessels has up to now commonly been investigated by neglecting the effect of sloshing. This paper deals with the effect of sloshing in tanks on motions and hull girder responses of oil tankers in various damage conditions and represents a part of a study to assess the effect of sloshing on hull girder failure of damaged vessels, The flooded tanks are assumed to have a of rectangular shape and linear multimodal approach is adopted to deal with sloshing. It is concluded that even though the effect of sloshing in tanks on the roll motion of vessels can be neglected in certain damage conditions, the effect of sloshing on the horizontal bending moment cannot be neglected, especially when resonance motion occurs.

Multi-Objective Optimization of Internal Compartment Layout of Oil Tankers

2019 ◽  
Vol 35 (4) ◽  
pp. 374-385 ◽  
Author(s):  
Hamidreza Jafaryeganeh ◽  
Manuel Ventura ◽  
Carlos Guedes Soares
Keyword(s):  
Bending Moment ◽  
Economic Benefits ◽  
Multi Objective Optimization ◽  
Safety Requirements ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Design Variables ◽  
Longitudinal Bending ◽  
Cargo Capacity ◽  
Oil Tankers

This work deals with the design of the internal layout of a shuttle tanker formulated as a multi-objective optimization problem, balancing cargo capacity and minimizing still water bending moment with safety requirements, in particular survivability after damage. A parametric model is used to specify the internal layout of a tanker ship considering a fixed hull shape and regulatory framework. The design variables include positions of watertight members in the internal layout, such as watertight bulkhead position, double-bottom height, and wing tanks width. Merit functions are the minimization of oil outflow parameter, maximization of cargo capacity, and minimization of the longitudinal bending moment, which are, respectively, represented for reduction of environmental pollution due to damaged oil tankers, improvement of economic benefits, and safety during operation. The multi-objective genetic algorithm is used for approaching the Pareto frontiers, and the choices between the optimal designs are discussed while introducing a utility function.

Toward a New Procedure for the Quantitative Risk Assessment of Double Hull Oil Tankers in Collisions

2015 ◽  
Author(s):  
Samy Adly Mansour Youssef ◽  
Serdar Turgut Ince ◽  
Yang Seop Kim ◽  
Muhammad Faisal ◽  
Jung Kwan Seo ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Residual Strength ◽  
Probabilistic Approach ◽  
Bending Moment ◽  
Quantitative Risk Assessment ◽  
Design Stage ◽  
Loading Ratio ◽  
Ship Collision ◽  
Oil Tankers ◽  
Double Hull

In recent decades, the number of ships increased substantially and it is still expected to continue to increase. Collision risk is one of the most serious accidents that can lead to severe consequences, such as casualty, property damage and environmental pollution. According to the statistics, it is found that the developments in collision avoidance systems and the related regulations have not contributed much to prevent the collision accidents. The aim of the present study is to develop a new methodology for the quantitative risk assessment of double–hull oil tankers. Within the framework of the methodology, a probabilistic approach is introduced to define a relevant set of ship–ship collision scenarios by treating the accidental influencing parameters as random variables. The collision frequency is calculated for each of the selected collision scenarios by considering a double–hull oil tanker collided with different types of striking ships. To predict the resulting collision damage to the struck ship, numerical simulations are conducted for each scenario by performing nonlinear finite element analyses. Based on the calculated risks, exceedance curves are established that can be used to define the collision design loads in association with various design criteria. In addition, to give a more complete picture of the risk assessment, a new method is proposed for assessing the risk of ship’s hull collapse following a collision. The results are formulated in terms of the residual strength index (RSI) and the loading ratio to produce the relationship between residual strength (R) and loading ratio of horizontal bending moment to vertical bending moment (L) and design formulations for predicting the RSI of damaged ship hulls are derived in an empirical manner. As an applied example, a hypothetical Suezmax–class double hull tanker is considered as a struck ship. Collision risks to asset and the environment are assessed. It is considered that the developed methodology can be useful in the early design stage of oil tankers.

Reliability Analysis of Oil Tankers With Collision Damage

2008 ◽  
Author(s):  
Huirong Jia ◽  
Torgeir Moan
Keyword(s):  
Reliability Analysis ◽  
Load Condition ◽  
Bending Moment ◽  
Bending Moments ◽  
Load Effect ◽  
Damage Scenarios ◽  
Interaction Equation ◽  
Hydrodynamic Code ◽  
Oil Tankers ◽  
Wave Induced

This paper deals with reliability analysis of a damaged tanker conditioned upon collision damage and the damage scenarios following collision. A tanker in full load condition (FLC) and two damage sizes are considered. The ultimate strength of the damaged tanker is assessed by applying Smith’s method, and an interaction equation for vertical and horizontal bending moments (VBM and HBM) is established. The still-water bending moment is calculated by the hydrostatic code ShipShape and the 3D hydrodynamic code WASIM is employed to calculate the wave induced vertical and horizontal bending moments. Correlation between vertical and horizontal bending moments is also considered. An out-crossing rate method is adopted to estimate the failure probability for the vector load effect process, and Monte Carlo simulations are used to account for model uncertainties.

A Fruitful Stochastic Model

1964 ◽  
Vol 9 (7) ◽  
pp. 273-276
Author(s):  
ANATOL RAPOPORT
Keyword(s):  
Stochastic Model

A Stochastic Model for Evolution of Altruistic Genes

1996 ◽  
Vol 6 (4) ◽  
pp. 445-453 ◽  
Author(s):  
Roberta Donato
Keyword(s):  
Stochastic Model

A Stochastic Model for the Inheritance of the Cancer Proneness Phenotype

1987 ◽  
Vol 26 (03) ◽  
pp. 117-123
Author(s):  
P. Tautu ◽  
G. Wagner
Keyword(s):  
Stochastic Model ◽  
Gaussian Process ◽  
Covariance Function ◽  
Neoplastic Disease ◽  
Disease Phenotype ◽  
Probabilistic Representation ◽  
Temporal Behaviour ◽  
Continuous Trait ◽  
Continuous Parameter ◽  
Level Zero

SummaryA continuous parameter, stationary Gaussian process is introduced as a first approach to the probabilistic representation of the phenotype inheritance process. With some specific assumptions about the components of the covariance function, it may describe the temporal behaviour of the “cancer-proneness phenotype” (CPF) as a quantitative continuous trait. Upcrossing a fixed level (“threshold”) u and reaching level zero are the extremes of the Gaussian process considered; it is assumed that they might be interpreted as the transformation of CPF into a “neoplastic disease phenotype” or as the non-proneness to cancer, respectively.

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